324 HARMOTHOE IMBRICATA. 



As shown in Plate XXVI a 5 fig. 9, the feet by-and-by assume a lobate form, and 

 the bristles lengthen, while two rounded papilla? mark the anal cirri. The body is com- 

 paratively broad and short, and the anterior end truncated. 



At a stage a little subsequent to the foregoing the head is better differentiated, and 

 the lateral tentacles appear as two rounded papilla? on each side of the median dimple. 

 There were ten feet in the example, and the scales were well formed. The tentacular 

 cirri had a single large (the largest in the animal) curved dorsal bristle projecting at the 

 base, with prominent rows of spines, and one or two smaller bristles just appearing 

 beyond the surface. The organs themselves showed indications of developing cilia, as 

 also did the dorsal cirri. Inferiorly the palpi formed two large rounded discs on each 

 side of the head, projecting laterally, but not yet reaching the front. No trace of a 

 median tentacle was observed in this specimen. The dorsal bristles were all curved, 

 with prominent rows of spines, and the tips of the ventral had also very distinct 

 spinous rows. The bristles project prominently (nectocha?te stage). No caudal styles 

 were present. 



In Plate XXVI a, fig. 10, the next stage is represented. The head is less bluntly 

 conical, and the two tentacular cirri are leaf-shaped, and soon the tip of the powerful 

 dorsal bristle at their base projects nearly straight outward. The body is more elon- 

 gated, the feet more prominent, and the bristles project more than half the diameter of 

 the body on each side. The caudal cirri are now broadly lanceolate. Minute scales are 

 present. 



The dorsal bristles resemble the ventral more closely than in the adult. Moreover 

 they approach those towards the posterior end of the adult rather than the median, a 

 fact which may be connected with the growth of new segments between those adjoining 

 the head and the tail. Thus it is that the anterior and posterior segments of the adult 

 show the primitive condition of the bristles, the most modified and the most typical 

 being those in the region between them. 



In the stage shown in Plate XXVI a, fig. 11, the median tentacle (which may have 

 been lost in the previous preparation) projects conspicuously in front, and the caudal 

 cirri with tapered extremities are distinct. 



In early stages, in which eight feet and four pairs of scales occur, the eyes on each 

 side are nearer each other than subsequently, and a smaller third black speck is observed 

 on each side in front of the rest on the under surface near the site of the adult eye, 

 though the peaks are not yet formed. 



In the stage figured in Plate XXVI a, fig. 12, the head is still further defined, the 

 eyes being arranged obliquely on each side (the posterior pair nearer each other than the 

 anterior). The median and lateral tentacles are distinct, and the palpi project promi- 

 nently forward, with tapering extremities. Their margins are crenatecl, but distinct 

 papilla? were not observed. The tentacular cirri show short clavate cilia. The scales 

 are larger, and have short clavate papilla? projecting from the outer border, the last 

 pair of scales having the largest cilia. The feet are deeply cleft and prominent, and the 

 slender shafts of the bristles have become greatly elongated, so that they project far 

 outwards on each side. There were nine bristled feet in the example. In this instance 



